In recent years, larger display devices have been required. Large display devices can be used for a television device for home use (also referred to as a TV or a television receiver), digital signage, and a public information display (PID), for example. A larger display region of a display device can provide more information at a time. In addition, a larger display region attracts more attention, so that the effectiveness of the advertisement is expected to be increased, for example.
Larger display devices have been also required for application to mobile devices. It has been considered to improve browsability by increasing the area of a display region of the display device to increase the amount of information to be displayed at a time.
Light-emitting elements utilizing electroluminescence (also referred to as EL elements) have features such as ease of thinning and lightening, high-speed response to an input signal, and driving with a direct-current low voltage source; thus, application of the EL elements to display devices has been proposed. For example, Patent Document 1 discloses an example of a display device including an organic EL element.
Patent Document 2 discloses a flexible active matrix light-emitting device in which an organic EL element and a transistor serving as a switching element are provided over a film substrate.